The present application is for renewal of support for a program of research in which a combination of behavioral, physiological and biochemical techniques are being used to learn more about the laws, mechanisms, and consequences of the instrumental learning of cardiovascular responses in noncurarized rats and squirrel monkeys. The present application also requests funds to support research to determine the reasons for the recent difficulty in replication of earlier experiments performed on curarized rats. In the proposed analysis of our replication difficulties, the following variables are to be investigated: Strain differences or the role of early experience, curarization procedures, respiration procedures, the search for possible artifacts, and the shift from heart rate to other viseral responses. New proposed experiments on noncurarized subjects will seek to elucidate the effects of cardiovascular training on emotionality and norepinephrine metabolism and to determine if the prolonged training of heart rate in rats and blood pressure in squirrel monkeys can produce sustained pathological effects. A final set of objectives is to determine the optimal conditions for training cardiovascular responses and to investigate the role of the somatic nervous system in producing and mediating cardiovascular changes.